Laboratory sifter



March 10, 1931. p o. L. MOORE LABORATORY SIETER Filed April 50, 1927 2 Sheets-Sheet 1 5 @71 J02 6 jz March 10, 1931. o. MOORE LABORATORY SIFTER Filed April 30 1927 2 Sheets-Sheet 2 Patented Mar. 10, 1931 ORLA L. MOORE, OF CHICAGO, ILLINOIS LABORATORY SIFTER 7 Application filed April 30,

The invention pertains to a cement testing machine, and particularly to a novel screen holding reciprocating truck cooperating with a hopper and discharge receptacle for the dispositionof cement screenings and the residue therefrom.

An object of the invention is to provide a truck carrying a plurality of screens both principal and auxiliary to dispose of cement screenings.

chine to more quickly handle material to be screened and to provide morecompact and etlicient screening means so that a maximum iscreening surface may be used without sacriicing lightnessor compactness of the n1achine.

Other and more specific objects will appear from the detailed description and drawings appended hereto. g In the drawings, wherein like reference characters areused to designate like parts Figure 1 isan end elevation of the apparatus showing the disposition of the various parts;

Figure 2 is a plan view of the gang plate of thescreening apparatus; and

Figure 3 is a side elevation of the gang plate shown in Figure 2;

Figure 4: is a plan view of the apparatus. showing the operating means therefor.

In this invention, it has been found desirable to build a frame 1 of any suitable ma terial, such as structural steel, which frame carries a suitable screen operating means 2, such as a motor, having any operating means, such as a jack shaft 100 provided with a pinion 101 meshing with pinion 102 provided on the crank shaft 103, said crank shaft being provided with a flywheel 104 for insuring ap- 1927. Serial No. 187,851

broxirnate constant rotation thereof. The

crank shaft is provided with cranks 105 'located at convenient places, the same being pivot-ally connected through links 106' with thegang plate 3 to the brackets 107. The frame also carries a'suitable track 4: for the Wheels 5 which support the under frame of the screen by suitable pedestals 5. The gang plate, which may be made of any suitable material such as aluminumpine or the like,

for lightness, may be of any length and has openings (5 therein of any number ada ted to have the screens 6 disposed therein. aid

screens are preferably semi-circular in, sideelevation andmay conveniently be disposed 1 between adjustable metal bands 14 suitably I supported on the gang plate and conveniently fastened thereto by clips 13 and 13 At the hinged end 8 of the gang plate, there is disposed an auxiliary screen 12 which is disposed in a frame separable from the frame of the main screen and attached to the main screen or gang plate in any suitable manner.

Disposed in the rear of the hinged end of the gang plate, there may be a support or platform 15, attached to the main frame 1. and adapted to hold the receptacle or beaker 10 into which the residue is poured through a usual funnel),

Under each screen there is a hopper 7, supported on the main frame 1 which leads into a conduit 7 provided with a fan or air blast for conducting the screenings to the proper receptacles. The hoppers 7 span a portion of the frame transversely under each screen'and are of a length at least equal to the travel of the screen. As before pointed out, the gang plate is hinged at 8 to the under frame and this gang plate is provided at the opposite end with a handle 3 for the purpose of dumping the residue into the beaker 10 when the gang plate is nearest that edge of the frame. i i

I In the operation of the screens, shot 108 is disposed in the main screen 11 for the purpose of hastening the sieving action. It is usual in sieving operation to take care of small variations in the sieve mesh by the use of a correction factor obtained from a standarclized sample or sieve, this factor to vbe added to or subtracted from each test result obtained on each screen. With this method, it will readily be understood that errors are liable to be introduced especially where several screens are involved and the work is handled by unskilled workmen. The shot used in this invention does away with the liability of this error for it will be appreciated that the shot rolling around loosely in the sieve prevents the particles from adhering to the walls of the sieve thereby maintaining the particles in a constantly agitated condition such that they flow from the screening apparatus in a substantially uniform or constant volume. Furthermore, when large particles of material are being operated upon, there is a tendency on the part of the shot to break these larger bodies up into minute particle which will flow at a substantially constant rate through the sieve to prevent the larger particles from clogging and otherwise interfering with the proper operation of the sieve. The weight of the shot to be used is adjusted by trial to bring all the sieves into line with the sample of known fineness when the machine is running at its working speed for a given period of time or for a given number of oscillations, and it has been found that when all the sieves are corrected for agiven set of conditions, no further attention need be paid to any correction thereof.

It will be understood that the material to be screened or tested is disposed in the main part of the sieve 11. The motor is started and the sieve reciprocated. Screenings will pass into the hopper 7 and be conducted away through the conduit 7. After this screening operation, there will be left in the main screen a mixture of the shot and the residue, which residue is the material desired for testing. The gang plate is then rotated through approximately 180 by means of the handle 3 and the residue passes through the coarser screen 12 which is, however, of sufficient fineness to act as a cage to retain the shot, into the funnel 9 and into the beaker 10.

It will be understood that I do not wish to be limited by the specific structure shown as other and obvious modifications will appear to those skilled in the art.

I claim:

1. An apparatus of the character described, comprising a screening device movable between an upright and an inverted position, said screening device having a curved lower surface for performing a screening operation while the device is in an upright positiomand being provided with a recessed portion in its top for receiving unscreened particles when the device is moved into an inverted position.

2. A screening apparatus including aframe supporting a plurality of successive differential screens to form a screening unit, the interior bottom of said unit being curved between said screens and said frame being pivotally mounted so that the contents may be poured gently from one screen to another, and means for reciprocating said frame to efiect a sifting operation.

3. A screening apparatus including a frame supporting a plurality of successive differential screens to form a screening unit, the interior bottom of said unit being curved between said screens and said frame being pivotally mounted so that the contents may be poured gently from one screen to another, means for reciprocating said frame to effect a sifting operation, undersize and oversize receivers, and means for tilting the frame to discharge oversize material into the oversize receiver.

4:. A screening apparatus including aframe supporting a plurality of successive differential screens to form a screening unit, the interior bottom of said unit beingcurved between said screens and said. frame being pivotally mounted so that the content may be poured gently from one screen to another, means for reciprocating said frame to eflect a sifting operation, an undersize receiver located to receive material passing through said first screen, and an oversize receiver located to receive material passing through the second screen after the frame hasbeen pivoted to pour the contents onto saidsecond screen.

5. A screening apparatus comprising, a plurality of successive screens, a'movable frame carrying said screens, an undersize receiving means located beneath the frame, means for imparting movement to the frame to cause a .screening operation to take place through one only of said screens above said undersize receiving means, an oversize receiving means located toward the rear of the movable frame for receiving oversize particles, said movable frame being adapted for pivotal displacement between two positions, in the first of which one screen is rendered effective over the undersize receiver and in the second of which positions the other screen is rendered effective over the oversize receiver, the contents being dumped from one screen to. the other by the pivotal displacement.

Signed at Chicago, Illinois,.this 23rd day of April, 1927.

ORLA L. MOORE. 

